The present invention relates generally to novel joints and devices employing members having a tubular configuration and more particularly to novel automotive suspension and support devices, such as anti-sway bars, torsion bars, and the like.
In automotive suspension and support systems, such components as anti-sway bars and torsion bars have been made from solid cylindrical metal stock. Typically, such stock would vary in diameter from 7/8 inch to 11/4 inch depending on the weight of the automobile and the particular ride characteristics desired. One problem with this prior construction is that components are typically quite heavy. For example, an anti-sway bar, sometimes referred to as a stabilizer bar, having a one inch diameter and a forty-two inch bushing to bushing length would weigh more than nine pounds. Typically, such anti-sway bars include one or more bends, as illustrated in U.S. Pat. No. 3,315,952. Although it is known that tubular material weights less than solid material, and although techniques for bending tubular material are also well-known, as illustrated in U.S. Pat. No. 1,903,436, to data no technique has been utilized successfully for making such anti-sway bars or torsion bars out of tubular material. The reason for this is that it is a characteristic of tubular material that once it is bent it is drastically weakened in the transition area. Thus, if the tubing is utilized in an application such as an anti-sway bar where a large amount of stress will be placed upon it, the tubing will tend to buckle and fail catastrophically in the transition area.